Analytical Methodology for Enzymatic Hydrolysis of Xylan
To judge how effectively sugars can be liberated from hemicelluloses by various methods, we must have the laboratory tools to measure the amount of sugars produced. Such tools are called analytical methods, and require instruments for separation of mixtures, such as high pressure liquid chromatography, and instruments for identification of the separated components, such as mass spectrometers. These instrument are the “magic” devices familiar to all who watch CSI programs on television. Unfortunately, in the real world, much more effort is required than is shown on television.
We have examined hydrolysis of birch xylan with both sulfuric acid and a xylanase enzyme from Trichoderma viride. While the acid hydrolysis is more rapid, it requires conditions that produce by-products such as methyl furfural, which hinder the further use of the liberated sugars. The enzymatic hydrolysis is found to be much cleaner, although proceeding in somewhat lower yields. Best methodology for quantitation of xylose involves hplc separation on a Shodex Asahipak NH2P-50 4E column under isocratic conditions with acetonitrile:water 3:1 as solvent, followed by mass spectrometry with room temperature chemical ionization.
Other Research Partners
LeRae Graham (PhD candidate) who is supported by the FBRI is the lead researcher on this project. She also has received support from the EPA through the New England Green Chemistry Consortium.
What’s New on this Project?
Experiments are underway with oxidatively delignified birch xylan to compare yields of xylose with yields from unoxidized xylan.